• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.11A
• /
• pp.891-897
• /
• 2009

In the satellite communications, the frequency sharing with other services is important because the service coverage is generally very wide and overlaps with those of other wireless services. This paper introduces a new technique to mitigate interference into the terrestrial stations from the Earth station in the same frequency band by means of band segmentations which are portions of the overall operation frequency band divided by frequency reuse factor. We consider a multi-beam satellite system, where frequency bands are reused in each satellite cell. The terrestrial stations use band segmentations of adjacent satellite cells, and this may decrease the interferences. By this way, the terrestrial and satellite systems can share the same frequency bands efficiently. The simulation is performed at frequency reuse factors, seven and three. The simulation results show that the proposed method can highly reduce the interference level to -168 dBW or -163 dBW depending on the considered frequency reuse factor from -117 dBW at the 90% link availability.

• Journal of Advanced Navigation Technology
• /
• v.14 no.6
• /
• pp.859-864
• /
• 2010

In the next generation system, a study on realization of Multi-Core system is in progress for applying it in multi service network. Therefore some mobile systems are expected to be appeared. These systems can support WiBro, WCDMA, CDMA, etc with single terminal. These systems have to support various FA using broadband frequency and hand over to other service network. Especially, in the telecommunication system composed of cell, the transmit power can be interference at adjacent system, has effect on system channel capacity and cell size. In this paper, we improve the unstable transmit power caused by unsettled system operation, propose the RF(Radio Frequency) Calibration method which can use the transmit power stably even during hand over between heterogeneous networks causing unstable power change. Also we used proposed method and analysed used electricity of system during hand over between heterogeneous networks.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.4
• /
• pp.11-19
• /
• 2007

A ubiquitous network environment is a system where the user can avail of the network's services anytime, anywhere. To establish such an environment, studies continue being conducted on wireless communication technology and mobile terminals. The company that provides such services should have an established system for authentication, authorization and charging for users. This service is referred to as Authentication, Authorization, Accounting(AAA), and its aspects have been consistently studied. On the other hand, existing studies have been promoted with regard to the authentication and efficiency of the mobile terminal. One of the method is that the mobile terminal contacts to the home authentication server through the external authentication server every time it is required and; another one is to use a medium server to provide authentication in the middle between them. Thus, this study aims to determine the best method to use ticketing, where tickets are provided through a mobile terminal, complete with authentication and authorization features. Also, as it uses ticket, it can efficiently provide mobile verification processing.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.12
• /
• pp.1890-1897
• /
• 2021

People counting is an important technology to provide application services such as smart home, smart building, smart car, etc. Due to the social distancing of COVID-19, the people counting technology attracted public attention. People counting system can be implemented in various ways such as camera, sensor, wireless, etc. according to service requirements. People counting system using WiFi AP uses WiFi CSI data that reflects multipath information. This technology is an effective solution implementing indoor with low cost. The conventional WiFi CSI-based people counting technologies have low accuracy that obstructs the high quality service. This paper proposes a deep learning people counting system based on WiFi CSI data. Data preprocessing using auto-encoder, data augmentation that transform WiFi CSI data, and a proposed deep learning model improve the accuracy of people counting. In the experimental result, the proposed approach shows 89.29% accuracy in 6 subjects.

• Journal of Digital Convergence
• /
• v.12 no.4
• /
• pp.335-342
• /
• 2014

According to the recent trends in the growing elderly population, the chronically ill have increased. Thus the importance of the health care issues for them has emerged. In this paper, we want to implement a chronic disease management system using smart mobile devices. Proposed chronic disease management system is consisted of the biometric sensor, smart mobile devices, the patient management server, patient management DB, and patient symptoms analysis agent. The biometric sensor detects a biological information. Smart mobile devices receive the patient information from the sensor and transmit the information to the patient management server. The patient management server, patient management DB, and patient symptoms agent analysis agent analyze to process data delivered through a wireless communication network. Bio-signals includes modules of ECG, blood pressure, blood sugar and PPG. We are able to determine the current health status by monitoring measured biometric data through chronically ill health management system. We will focus on the individual service to be appropriate for a patient group in a mobile environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.6
• /
• pp.275-280
• /
• 2010

Recently, This paper suggests that LED-ID technique applying positioning method for LED light. also, Authors in this paper has launched this investigation earnestly. However, there are various interferences such as MPI(Multi Path Interference) by reflected waves of the surface and interfere factors by their correlation properties of the ID in LED-ID wireless channel. Therefore, in this paper, we propose a novel OOK(On-Off Keying)-CDMA(Code Division Multiple Access) system using unipolar ZCD(Zero Correlation Duration) spreading code and verify the availability of the proposed system via the evaluation performance simulation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.7
• /
• pp.1389-1397
• /
• 2016

This study was to evaluate opportunities for the commercialization of smart insole. smart technology is evolving to Insole. Pressure-sensitive sensor or an acceleration sensor is applied to create a balance of the feet and body, is also evolving for entertainment (sports, entertainment, etc.) and health care. Moreover, smart insole can fix an incorrect walking habit by sending a weight value measured by the sensor on a smartphone and during the movement, smart insole helps to correct body balance by measuring the center of gravity moving condition. However, smart tendency of the insole has yet to create a clear boundary in the entertainment and healthcare markets. This is because the fitness band, smart socks, smart shoes can also replace the benefits of a smart insole. Interestingly, the business opportunities are appearing more frequently in health care solution service of electrocardiogram, body temperature, blood pressure, etc., rather than smart devices.

• Journal of the Korea Convergence Society
• /
• v.7 no.4
• /
• pp.33-38
• /
• 2016

DDoS attack has been continuously utilized that caused the excessively large amount of traffic that network bandwidth or server was unable to deal with paralyzing the service. Most of the people regard NTP as the biggest cause of DDoS. However, according to recently executed DDoS attack, there have been many SSDP attack in the use of amplified technique. According to characteristics of SSDP, there is no connection for making a forgery of source IP address and amplified resources feasible. Therefore, it is frequently used for attack. Especially, as it is mostly used as a protocol for causing DDoS attack on IoT devices that constitute smart home including a wireless router, media server, webcam, smart TV, and network printer. Hereupon, it is anticipated for servers of attacks to gradually increase. This might cause a serious threat to major information of human lives, major government bodies, and company system as well as on IoT devices. This study is intended to identify DDoS attack techniques in the use of weakness of SSDP protocol occurring in IoT devices and attacking scenario and counter-measures on them.

• Journal of Korea Spatial Information System Society
• /
• v.10 no.4
• /
• pp.103-107
• /
• 2008

This study mainly focused on the development of real-time based damage investigation system using web-GIS. The study area was Gangseo-Gu in Busan where frequently has relatively higher magnitude of damages from natural disasters. GIS DB was built to provide geospatial data such as 1:1,000 and 1:5,000 topographic maps and IKONOS high resolution satellite data. The web-GIS system has demonstrated the higher contribution for the better response and recovery against any type of natural disasters through real-time communication and data dissemination among government agencies and personnel. However, further researches need to be made to improve system capabilities. In addition, for more effective system operation and maximizing the benefits of exploiting web-GIS system, linkage with national DB such as NDMS is essential.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.4 s.346
• /
• pp.1-12
• /
• 2006

In this paper we propose an efficient mobile multimedia communication protocol, mobile terminal software platform and mobile VoIP application for IP-based convergence networks. The Proposed mobile multimedia communication protocol is called as ST-MRSVP (Split tunnel based Mobile Resource reServation Protocol) which integrates split tunnel based Mobile IP and RSVP in order to support hish speed mobility. Since mobile terminal platform supports QoS (Qualify of Service) with keeping seamless mobility, mobile QoS supporting modules are developed and interworked together by means of shared memory mechanism. Testbed is composed of a core-network embedding the proposed protocols and wireless LAN-based access networks. We verify functionality and performance of the proposed techniques by using various mobility test over the testbed. As a result, the proposed architecture can reduce the handover delay time with QoS support under 30% comparing with the standard mechanisms and support voice quality as good as CDMA phone.